Microwave ultrasonic apparatus



June 24, 1969 I M. L. LEVlNSON 3,451,401

MI CROWAVE ULTRASONI C APPARATUS Filed on. 12, 19s? United States Patent 9 Claims ABSTRACT OF THE DISCLOSURE A multi-function apparatus capable of operating as an ultrasonic cleaner and microwave oven, which features the use of an ultrasonic emitting means, a microwave emitting means, and an implement capable of converting at least a portion of the emitting microwave energy into heat energy. The apparatus also features the use of circuitry capable of operating the ultrasonic and microwave emitting means either simultaneously or sequentially from a common power supply.

Cross references to related applications This invention relates to microwave and ultrasonic apparatus, and particularly to a microwave-ultrasonic apparatus capable of performing numerous household and industrial functions.

In living areas where space is a premium, such as a mobile home, camping trailer, small apartment, small dwelling or the like, it is apparent that the numerous household items required for maintaining a household are space consuming and expensive. For example, it is most common to find a washer, dryer, dishwasher, oven, exhaust fan and the like in ones kitchen area. Also, even with commercial enterprises, such as hotels and restaurants, the aggregate cost of these items are high and the space occupied is great. As a result, single type apparatus have been invented which are capable of performing the function of a plurality of different appliances which include washers, dishwashers, driers, ovens and the like. A typical example of such single type apparatus having multi-functions may be found in my copending U.S. application, Ser. No. 594,964.

The above-discussed multi-function type apparatus employs microwave and ultrasonic energy in the utilities thereof. Accordingly, I have found it extremely desirable to provide such an apparatus having high efliciency and low cost. To this end, a unique microwave absorbing implement is employed with the microwave generator which causes it to operate at a relatively higher efficiency, thereby enhancing the utility of the apparatus. Further, the microwave generator is caused to operate from the ultrasonic power source, thereby reducing the bulk and cost as sociated therewith.

Summary of the invention Accordingly, it is an object of this invention to provide a multi-function, microwave-ultrasonic type apparatus with an improved power and control structure.

It is another object of this invention to provide a multi- 3,451,401 Patented June 24, 1969 function type apparatus having an improved heating and loading unit utilized therein.

In general, the invention according to the objects, is a multi-function type apparatus capable of selectively functioning as a microwave oven and an ultrasonic cleaner, such as a washer or a dishwasher, and includes means for emitting microwave energy for heating a workload, means for emitting ultrasonic energy to said workload, means for selectively controlling the operation of said microwave and ultrasonic emitting means, and means responsive to the operation of the microwave emitting means for converting at least a part of the microwave energy to heat energy for heating the workload.

In one embodiment, the apparatus includes a work treating chamber having side and bottom wall surfaces adapted to retain treating liquid within said chamber, means in the chamber for supporting a workload to be treated therein, a microwave generator disposed in a portion of said chamber in such a position to expose said workload to a field of microwave energy, an ultrasonictransducer disposed in a portion of said chamber in such a position to subject a liquid in which the workload may be immersed to ultrasonic pulsations, closure means for the chamber, a microwave absorbing heating implement within said chamber, and means for energizing said microwave generator and ultrasonic transducer either simultaneously or sequentially.

Brief description of the drawing The drawing is a cross-sectional view of the inventive apparatus with related circuitry.

Description of the preferred embodiment Since this apparatus is capable of being utilized for many various functions, the apparatus will first be described generally and then in detail with respect to particular utilities thereof.

The apparatus includes a housing 10 having a work treating chamber 11 formed by side wall surfaces 12-12 and a slanted bottom surface 13, said chamber 11 being adapted for retaining a liquid and microwave energy therein. A door 14 having an air intake window 15 and a handle 16 thereon is provided for access to the work chamber 11. Supporting elements 17-17 are provided for holding various type removable shalves 18, 18a thereon. A rim gasket 21 is provided on door 14 to prevent the escape of microwave energy from the chamber when the door is closed.

Shelves 18, 18a may take various forms, e.g., one may take the form of a microwave oven shelf 18 or another may take the form of a dishwasher shelf 18a for holding dishes thereon. Shelves, generally, are made of-material which is permeable to microwave energy and constructed as grids, grills or other conventional shapes transparent to water.

Shelf 18a, is transparent to water and microwave energy and is constructed so as to provide a removable, metallic grid enclosure 19 for holding articles, such as silverware and cutlery, which are subject to arcing when exposed to microwave energy. Openings 20-20 on the grid enclosure 19 are of any suitable size, e.g., approximately 4;", which is sufiiciently small to prevent microwave energy from passing therethrough (so as to prevent unwanted arcing throughout the silverware), but large enough for permitting fluids, ultrasonic energy and heat to pass therethrough. The metal grid enclosure 19 is located at a sufficient distance from walls 12-12 to prevent any unwanted arcing therewith.

A microwave-absorbing heating implement 2.5 may be utilized on a microwave oven shelf 18 or may even be in the form of a shelf per se (not shown). Numerous microwave-absorbing heating implements 25 are disclosed and more fully described in my copending US. applications 470,809; 483,144; 497,851; 589,626. Briefly, the implement 25 includes a bed or layer 26- of particles of a resistive material, such as ferrite, supported on an insulating medium 27 which may be of a material such as GR 25, manufactured by General Refractories Company. Bed 26 and insulating medium 27 are encased in a microwave, permeable waterproof casing 2 8, preferably made of a glass-ceramic type material such as 'Pyroceram (manufactured by Corning Glass Works) or Cer-Vit (manufactured by Owens-Illinois). The top portion of casing 28 is capable of use as a cooking surface 29, described here and after. When a foodstuff or other work load is not present in chamber 11, the ferrite bed 26 serves as a workload for a microwave emitter 30 such as a magnetron, and accordingly reflected microwave are substantially precluded, thereby preventing damage to the emitter. Said another way, upon energizing the micro wave emitter 30, the emitted microwaves contact the ferrite bed 26 which, in turn, transforms electrical energy into heat energy. In actuality, tiny electric arcs are initiated throughout the ferrite particles and within a very short time, the particle bed appears as if it was a glowing bed of coal emitting a high degree of heat. The heat generated is dependent on the amount and size of the ferrite particles, the quantity of the released microwave energy and time. As will be seen, when the apparatus is used as either a dishwasher or an oven, implement 25 will be useful.

A first transducer 35 is connected to the housing and when energized, emits mechanical ultrasonic energy through the apparatus. As will be seen, the first transducer 35 will be of service when the apparatus is used as a dishwasher. A second transducer 36, connected to a common power source 40, is located external the housing 10 and functions as an accessory for other uses external the apparatus. For example, the second transducer 36 may be manually positioned in a washing container, such as a sink, for imparting mechanical ultrasonic pulsations to a cleaning fluid therein for cleaning utensils. Another use of the second transducer 36 may be for its quick connection to a scrub head which is utilized to effortlessly scrub floors or other hard surfaces. It should be understood that while two functions of the second transducer 36 have been recited, numerous other functions may be possible without departing from the spirit of this invention.

A conventional high wattage ultrasonic power source 40, preferably a transistorized oscillator capable of emitting ultrasonic frequencies, is connected into a control circuit (not shown) operated by a programmer 41 which is selectively programmed to operate the apparatus for any one of its intended functions. Typical circuitry for operating the various control circuits may be found in my copending U.S. application, Ser. No. 594,964.

The high wattage, ultrasonic power source 40 is coupled to the first transducer 35 when the dual shorting contacts of switch 42 close contacts A and B; and to the second transducer 36 when the switch 42 closes contacts D and B. When switch 42 closes contacts C and D, power is supplied to the microwave emitter 30 via converter 43. The microwave emitter 30 and first transducer 35 may be operated simultaneously when switch 42 closes contacts B and C, thereby permitting one voltage to pass not only through contact B to the first transducer 35, but also to pass through contact C to converter '43 which, in turn, transforms said voltage to a desired voltage necessary to operate microwave generator emitter 30.

Converter 43 converts the output of the power source 40 into a suitable input for the microwave emitter 30. Compared to a conventional 60 cycle power source, the high frequency output of the ultrasonic power source 40 provides a dramatic reduction in the physical size of the transformer and/or the condenser rectifier voltage multiplier circuits of converter 43. As a result, the power supplies are shown in series rather than two individual 60 cycle parallel units.

The apparatus is further provided with inlets 50 and 51 for permitting the passage of hot and cold water into chamber 11 through valve 52. Waste liquids are removed from the chamber by a pump 53, located adjacent a drain cavity 54, for withdrawal through tube 55. A grid 56, similar to the type utilized for the silverware enclosure 19, is provided at the bottom of chamber 11 to not only negate the escape of microwave energy but also to permit liquid and forced air to pass therethrough.

,When the chamber 11 is not filled with a liquid, a reversable type fan 60 and air tube 61 are provided for removal of steam from chamber 11. More detailed use of fan 60 is described hereinafter when the apparatus is used as a dishwasher.

It should be noted that water inputs 50 and 51, air exhaust tube 61 and drain tube 55 are illustrated and shown one above the other for ease in illustration. In practice they would be best found exiting and entering side by side at a level corresponding to input 50.

Now that the apparatus has been described generally, further description will be directed to the use of the apparatus as a microwave oven and dishwasher.

Apparatus utilized as a microwave oven With dishwasher shelf 18 removed from chamber 11, a microwave oven shelf (not shown) is added on which is relocated implement 25. The programmer 41 is set to operate a circuit (not shown) which causes switch 42 to move and close contacts C and D, and power source 40 is energized. Converter 43 converts the output of the power source 40 to the desired voltage for the microwave emitter 30'. Microwave energy fills chamber 11 causing the ferrite bed 26 of implement 25 to transform the microwave energy into heat energy. By such action, implement 25 loads the microwave emitter 30, thereby preventing any burn-out from reflected power. After the implement 25 is charged with heat, microwave emitter 30 is turned off and a desired foodstuff or workload is located on the implement, the workload being seared and browned as a result of the stored heat in the implement being released. The microwave emitter 30 is caused to again operate for the time desired to cook the workload. The implement 25 is then taken fro-m chamber 11 to a remote location, whereupon the foodstuff may either be removed immediately from implement 25 or allowed to remain on implement 25 for further cooking, since heat continues to be released from the implement.

'It should be noted that, while one cooking technique has been described, various other cooking techniques may be employed. For example, the implement 25 could be in the form of a cooking shelf, per se, and/or the workload could be placed on the implement without any preheating thereof. Further, two implements can be provided in opposing relationship to each other so as to cook the foodstuff from the top and bottom simultaneously in a manner similar to a sandwich grill.

Apparatus used as a dishwasher After, shelf 18 and implement 25 are located in chamber 11, dishwasher shelf 18a is positioned in the chamber whereupon dishes are placed thereon, and silverware and other objetcs subject to microwave arcing damage are place in protective grid enclosure 19. The programmer 41 is set to operate a conventional dishwasher circuit (not shown), whereupon water is caused to flow into chamber 11 from inlets 50, '51. Switch 42 is caused to close contacts A and B to energize the ultrasonic transducer 35 which emits mechanical ultrasonic energy to ultrasonically clean the work and to emulsify any waste fats therefrom. Optionally, the switch 42 may be caused to move to close contacts B and C, thereby energizing the transducer 35 and microwave generator 30 simultaneously so as to permit not only the emission of ultrasonic energy into the chamber, but also the emission of microwave energy to impart additional heat to the water. After the work is cleansed and the waste fats are emulsified by ultransonics, the waste water is pumped by pump 53 from chamber 11 out through tube 55. After a conventional rinse cycle, switch 42 closes contacts C and D so that only the microwave emitter 30 is energized to fill chamber 11 with microwave energy. It should be noted that the water on the work (dishes) serves as the primary source of the microwave emitter 30s load, thereby causing the work (dishes) to dry rapidly. As the quantity of water on the work becomes less and less, the internal arcing of the particle layer 26 becomes more and more prevalent, causing the implement 25 to take over as the primary load for the microwave emitter 30. It can be seen that the ability of the heating implement 25 to convert microwave energy into heat energy as inversely proportional to the amount of water in chamber 11.

During the drying of the work, fan 60 is operated to take out hot moist air from chamber 11. This is accomplished by fan '60 drawing air through intake window 15, chamber 11, through grid enclosure 19, drain caivity 54 and eventually out through exit tube 61. As a result of the reduction of water in the chamber and a correspond ing increase of arcing in implement 25, a temperature rise is sensed by a heat sensor '63, which causes the control circuit to open and deactivate the apparatus.

Although this invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention. For example, while a apparatus has been described as a microwave oven, dishwasher and accessory unit, other uses are readily apparent, such as those commonly asociated with ultrasonic units (e.g., medial applications, tenderizing meat and the like).

I calim:

1. A multi-function, microwave-ultrasonic apparatus, which comprises, means for emitting microwave energy to a wor-kload, means for emitting ultrasonic energy to said workload, means for selectively controlling the operation of said microwave and ultrasonic emitting means, means responsive to the operation of the microwave emitting means for converting at least a part of the microwave energy to heat energy for heating the workload said responsive means comprising an implement having a bed of resistive particles having an insulating layer on one side of said bed of particles, and a removably located shelf for holding a first workload thereon capable of receiving microwave energy and a grid enclosure for holding a second workload therein, said enclosure being of such a grid size which is sufficiently small to prevent microwave energy from passing therethrough but sufficiently large to permit heat, liquid and ultrasonic energy to pass therethrough.

2. An apparatus, according to claim 1, wherein the implement is further provided with a cooking surface located on the other side of the particle bed.

3. An apparatus, according to claim 1, wherein the resistive particles are of a ferrite material.

4. An apparatus, according to claim 1, which includes a second ultrasonic emitting means connected to the apparatus for use external of the apparatus.

5. An apparatus, according to claim 1, which is capable of selectively opearting as an ultrasonic cleaner and a microwave oven.

'6. An apparatus, according to claim 1, wherein the selective controlling means includes a common power supply, a switch first, second, third and fourth contacts for said switch, and means for energizing the power supply and activating the switch whereupon a closing of the first and second contacts energize the ultrasonic emitting means, a closing of the second and third contacts energizethe ultrasonic and microwave emitting means simultaneously, and a closing of the third and fourth contacts energize the microwave emitting means solely.

7. An apparatus, according to claim 6, wherein a first voltage is emitted from the power supply, and wherein a converter is provided for converting the first voltage of the power supply to a second voltage for energization of the microwave emitting means.

8. An apparatus, according to claim 6, which includes a fifth contact and a second ultrasonic emitting means capable of use external of the apparatus, said second ultrasonic emitting means being energized upon a closing of the fourth and fifth contacts by the switch.

*9. A multifunction apparatus, which comprises, a work treating chamber having side and bottom wall surfaces adapted to retain treating liquid within said chamber, means in the chamber for supporting a workload to be treated therein, a microwave generator disposed in a portion of said chamber in such a position to expose said workload to a field of microwave energy, a first ultrasonic transducer disposed in a portion of said chamber in such a position to subject a liquid in which the workload may be immersed to ultrasonic energy, a second ultrasonic emitting means connected to the apparatus for use external of the apparatus, closure means for the chamber, a microwave absorbing heating implement within said chamber, having an insulating layer on one side and a cooking surafce on the other side means for energizing said microwave generator and ultrasonic transducer either simultaneously or sequentially, means for permitting the flow of liquid into the chamber, means for withdrawing waste liquid from said chamber, and means for withdrawing generated hot, moist air from said chamber.

References Cited UNITED STATES PATENTS 1,671,557 5N1928 Tyler 134-58 XR 2,216,388 10/1940 Hampel 134-58 XR 2,985,003 5/1961 Gelfand et al 68-3 3,184,400 5/1965 Magnus 204-193 3,329,529 7/1967 Lamar 134-58 3,410,116 11/1968 Levinson 6 8-3 OTHER REFERENCES German printed application Serial No. 1,120,619, Dec. 28, 1961, Homann.

ROBERT L. BLEUTGE, Primary Examiner.

U.S. Cl. X.R. 68-3; 134-1, 105, 115, 184; 219-10155 @2 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. iflyil lml Dated 1 25 1959 Inventor-(s) MEI QIN 1 L EVINSON It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 39, replace "medial" with --med1oal-.

SIGNED ANU SEALED DEC 2 1959 EdwardM-Flmhmlr. mm m W A. E. 0 m 0mm Oomissioner of Patents 

